Telecommunications apparatus, system, and method with an enhanced signal transfer point

ABSTRACT

The present invention is an apparatus, system, and method for converting point codes in a signal transfer point in a telecommunications signaling system. The STP converts point codes which designate the origination and destination signaling points for the message. The conversion is based on information defined by the messages, such as origination or destination information. The present invention creates a virtual signaling system which can be reconfigured at the STP by converting point codes, and thus, altering the identities of the signaling points. The present invention is also operable to convert circuit identification codes and transfer integrated services user part messages to a user part.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of prior application Ser. No.08/525,868, filed on Sep. 8, 1995, U.S. Pat. No. 5,926,482 and that isherein incorporated by reference into this application.

BACKGROUND

1. Field of the Invention

The invention relates to telecommunications and specifically to anenhanced signal transfer point (STP) which alters the point codes intelecommunications signaling and supports User Parts in addition toproviding standard STP functionality. The enhanced STP can form aportion of a telecommunications system.

2. Description of the Prior Art

Telecommunications signaling is the transfer of information within andamong telecommunications networks for use by the networks. Signalinginformation is used to operate the telecommunications networks so thesenetworks can transfer other non-signaling information for the networkusers. A few examples of signaling operations are call set-up,congestion control, and network management, although there are manysignaling operations. One well known telecommunications signaling systemis Signaling System #7 (SS7). At present, SS7 is the primary signalingsystem used by United States telecommunications providers.

As is known in the art, and as will be discussed below, STPs route SS7signaling within the SS7 network and manage the various signaling linkswhich comprise the SS7 network. Routing is accomplished by processingthe routing label of the SS7 message by the Message Transfer Part (MTP)functionality of the signaling point. The MTP is comprised of threelevels. Levels 1 and 2 facilitate the transfer of SS7 messages from onepoint to another over an individual signaling link. Level 3 facilitatesthe transfer of SS7 messages over the SS7 network beyond therequirements of individual link transmission. In other words, levels 1and 2 are concerned with transport over individual links whereas level 3is concerned with transport over the SS7 network in general.

An STP accomplishes its routing task at level 3 through the use of pointcodes which identify the various signaling points in the network. TheSTP level 3 will identify the destination point code in an SS7 messageand select the proper signaling link for routing that message. Forexample, if switch A signals a switch B through an STP, the message willcontain the destination point code for the signaling point in switch B(and the originating point code for switch A). The STP will accept thissignal off of one signaling link, read the destination point code, andplace the message on the appropriate link for switch B.

An STP can also control the signaling network through the use ofmanagement messages generated at level 3. In the above example, if therewere signaling links between switch A and the STP, the STP might signalswitch A with instructions to avoid particular links which werecongested or had failed.

Telecommunications networks are commonly faced with the problem ofre-routing user traffic among switches. Traffic may need to be re-routedfrom one switch to another switch, from one switch to multiple switches,from multiple switches to one switch, or from one group of switches to adifferent group of switches. When traffic accessing a network isdirected to a particular switch, the traffic is described as being homedto the switch. Traffic being homed to particular switches may need to bere-homed to other switches.

Re-routing the user traffic encompasses changing the connections betweenthe switches. Connections between switches may be added and deleted tocreate new network architectures. Due to the relationship betweensignaling and network architecture, any change in architecture needs tobe reflected in the signaling system. A common method for doing this isto re-program the switches to signal each other in accord with the newarchitecture. This a complex and time consuming task. Switches containnumerous data files which must be re-programmed in accordance with thenew routing scheme.

One prior art system facilitated the transition of trunks from an oldswitch to a new switch. The system converted the point codes insignaling messages directed to the old switch in response to a change ina trunk assignment from the old switch to the new switch. The converterwas placed between the switch and the STP so that it only handledsignaling on the signaling link connected to the old switch. It used alook-up table to yield the point codes. Since particular trunks would beconnected to either the new switch or the old switch based on anassignment, a table could be constructed to identify the particulartrunk used on a call and convert point codes based on thistrunk/switch/point code assignment. The prior art suggests placing thisconversion function in an STP, but it does not disclose more on thispoint.

Although this prior art system may be adequate for the limited scenarioencompassing the transition of individual trunks from an old switch to anew switch, it does not address the problem of changing networkarchitectures beyond this limited scenario. The prior art system isdesigned to serve two switches which share a single switch load and acommon signaling destination. In other words, the system is limited to asituation in which signaling which has already been routed to the oldswitch is split between the old switch and the new switch during thetransition of loads between the two switches.

As a result of this limitation, several problems are not addressed bythe prior art system. Since it is based on identifying individual trunksfor point code conversion, signals that cannot be associated with aspecific trunk would not be able to have their point codes converted.The prior art system does not address the problem of handling managementmessages which are generated for the control of the signaling system.Also, the reliance on individual trunk identification does notadequately address situations in which entire switch loads are movedbetween switches, or when multiple switch loads are consolidated on asingle switch. Because all trunks between switches are being changedover, individual trunk recognition is unnecessary.

Importantly, the prior art system does not identify the origination ofthe signaling message in order to select a destination for thesignaling. The prior art system does screen the messages which originatefrom the new switch so these signals can be converted to represent theold switch as the source of the signaling. This is done in order toavoid confusion at the destination, but it does not affect the actualselection of the destination. In the prior art system, the destinationis not chosen based on the origin of the message. The prior art systemuses only trunk identification to choose the destination. This isdetected using either the dialed number or the Circuit IdentificationCode (CIC).

It is also important to note that the prior art system is designed onlyto convert signaling that has been placed on the signaling linkconnected to the old switch. This means the STP has already isolated thesignaling messages as directed to the old switch. Thus, the system doesnot see signaling directed to any other switch, and it is not equippedto process signaling that has not been directed to the old switch. Assuch, an STP incorporating this system would convert the point codesonly after the STP has performed routing processing and designated thesignaling as being directed to the old switch. Thus, the STP of theprior art system would not apply to a conversion function for incomingsignals which had yet to be routed and could still be directed to anyswitch.

Another prior art system provides a signaling gateway between twosignaling systems, for example, a gateway for the signaling systems ofEurope and the United States. The signaling gateway converts point codesbased on the network identification and the destination point code. Thegateway does not convert point codes based on originating information,such as the signaling link or the originating point code. The gatewayalso converts point codes after the destination point code has been usedfor message routing. Also, since the gateway must interface signaling ofdifferent signaling systems, it necessarily includes more functionalityand cost than a point code converter that does not have gatewayfunctionality.

The above-referenced application discloses a signaling processor. Thesignaling processor receives, processes and transmits signaling. In someinstances, the signaling processor will not have a point code tofacilitate the routing of signaling messages. In other instances, thesignaling processor may receive signaling that was actually transmittedto a switch, but needs to be processed by the signaling processorinstead of the switch. The prior art does not address the signalingtransfer needs of these signaling processors.

Typically, an STP routes signaling among several switches. Presentsystems do not provide an efficient and workable STP which can convertsignaling in a way that accounts for architectural changes affectingseveral of the switches. At present, there is a need for an STP that canbetter facilitate architecture changes in a telecommunications network.

SUMMARY

The present invention is an STP, a system, and a method that solves theproblems posed by changes in architecture and the needs of signalingprocessors. The STP applies Message Transfer Part (MTP) functions tosignaling messages that contain point codes. A first means applies thesignaling data link function, a second means applies the signaling linkfunction, and a third means applies the signaling network function. Aconverting means is added for converting at least some of the pointcodes in the signaling messages into different point codes.

The converting means can be located between the second means and therouting function of the third means. Point code conversion may be basedon the point codes originally contained in the messages or onorigination information, such as the particular signaling linksets onwhich the messages are transferred to the STP. MTP level 3 managementmessages are also converted. The converting means could be comprised ofa table which is entered using the point codes or linkset designationsand which yields the converted codes. In addition, CircuitIdentification Codes (CICs) can be converted along with the point codes.

The present invention is operable to transfer integrated services userpart (ISUP) messages to any user parts coupled to the STP. The userparts may include signaling processors.

A signaling system embodying the invention is comprised of multiplesignaling points linked to a signal transfer point. The links can bedirect or through other STPs. The signaling points generate and processsignaling messages and transfer them to the STP over the links. Thesignaling messages contain codes that identify origination signalingpoints and destination signaling points for the messages. The STP isenhanced in accord with the present invention and is operable to convertdestination codes for signaling messages directed to a plurality ofsignaling points.

A method embodying the present invention includes receiving a signalingmessage into the signal transfer point from an originating signalingpoint. The signaling message contains codes which identify theorigination signaling point and the destination signaling point for themessage. The STP then converts at least a portion of the codes in themessage to different codes before the signaling message has beendesignated by the STP for a particular destination signaling point. TheSTP then transfers the signaling message to a signaling link based onthe converted codes. The conversions can be based on the codes in theinitial message and/or on a particular linkset the signaling message isreceived on.

In one embodiment, telecommunications traffic is re-routed amongswitches. However, the signaling points in the switches are notreprogrammed and continue to generate and transmit signaling to the STPaccording to the old architecture. The STP converts the point codes inthe messages to identify the switch that actually receives the trafficafter the re-route, and routes message to that switch according to theconverted destination point code.

Advantageously, the conversion function is located prior to the MTPlevel 3 route function allowing a single integrated and flexible system.Conversions selecting a destination can be based on the origin of thesignaling. Management messages are also converted to facilitate controlof the signaling system.

In another embodiment, the point codes in signaling messages areconverted between the point code of a signaling processor and the pointcode of other signaling points. This might occur if signaling is beingrouted to a signaling processor instead of a switch even though thesignaling message identifies the destination point code of the switch.Messages from the signaling processor may need to have the originatingpoint code converted to another point code, i.e. the switch that was toreceive the initial message. In another embodiment, the signalingprocessor could be a user part of the STP and require that selectsignaling messages are routed through the signaling processor.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood with regard to the followingdescription, claims, and drawings where:

FIG. 1 is a block diagram of a signaling system.

FIG. 2 is a block diagram of a telecommunications network including asignaling system.

FIG. 3 is a logical diagram of SS7 functionality.

FIG. 4 is a logical diagram of a version of the invention.

FIG. 5 is a logical diagram of a version of the invention.

FIG. 6 is a logical diagram of a version of the invention.

FIG. 7 is a block diagram of a version of the invention.

FIG. 8 is a block diagram of a version of the invention.

DESCRIPTION

As those skilled in the art are aware, SS7 systems are currentlycomprised of basic components such as, signaling points, signalingtransfer points (STPs), and signaling links. Signaling points processthe signaling information to facilitate network operations. Signalinglinks transfer this signaling information among the various signalingpoints. FIG. 1 is provided to illustrate this basic relationship and itshows a basic signaling system comprised of signaling points 10-15 andsignaling links 20-28. Links 20-28 carry signaling used to operate thenetwork, and the actual lines which carry telecommunications traffic arenot shown.

A common example of a signaling link is a 56 k/bit data link containedin a T1 line. However, these links can take many different forms such asanalog links, satellite links, and 1.5 M/bit data links. Typically, thelinks are grouped into multiple associations of links called linksets.

Signaling points process the signaling information transferred by thesignaling links. Often, a signaling point is located within atelecommunications switch. As is known, switches typically include acentral processing unit (CPU), a signaling point, and a switch matrix.The signaling point is connected to the switch CPU and provides the CPUwith data so it can control the switch matrix. Switches will communicateto each other through their signaling points over the signaling links.In this way, the various switch matrices can be coordinated by theswitch CPUs to establish a connection through a series of switches.

Signaling points can also be located in Service Control Points (SCPs).As those skilled in the art are aware, SCPs include databases thatrespond to signaling from switches. Typically, the SCP will accept aquery from a switch as to how a particular call should be routed. TheSCP will process the signal and respond to the switch with a signal thatprovides routing information.

STPs can function as a signaling point in addition to the signalingtransfer function. The STP accepts multiple signaling links fromnumerous signaling points. The STP's primary function is routing;placing incoming signaling on the appropriate outgoing signaling link.Typically, the signaling points in switches and SCPs are linked to STPsand transmit signaling to the STPs for routing to the proper destinationsignaling point in another switch or SCP. STPs also perform managementfunctions for the SS7 network.

Other types of signaling points are equally applicable to the presentinvention. For example, the above referenced signaling processors canfunction as signaling points. In addition, other signaling systems, suchas C7 signaling, are equally applicable to the present invention.

FIG. 2 further illustrates the basic relationship of FIG. 1 and is anoverlay of FIG. 1. FIG. 2 shows switches 30-32, STPs 40-41, signalingprocessor 45, and SCP 50 which each include a signaling point that islinked to signaling points in other network elements. As discussed, thesignaling points in the switches are typically coupled with a switch CPUthat controls the switch matrix.

The SS7 signal itself is a packet, or message, of information bits. Thefunctionality which processes SS7 signaling messages is fundamentallydivided into two parts: the Message Transfer Part (MTP), and the UserPart. The function of the MTP is to provide transport for the SS7messages within the signaling system. Those skilled in the art arefamiliar with functions in the User Part, such as the Integrated ServiceUser Part (ISUP), the Telephone User Part (TUP), the TransactionCapabilities Application Part (TCAP), and the Signaling ConnectionControl Part (SCCP). These functions “use” the MTP to transfer signalingmessages over the signaling links of the SS7 network so that the UserPart may process information required by the switches such as dialednumbers, translation numbers, and circuit status.

Since STPs serve to route and manage the SS7 network, they do notrequire User Part functionality which pertains to information aboutcalls and connections in the general telecommunications network. STPsare concerned with being able to route SS7 messages within the signalingnetwork to the appropriate signaling points in switches and SCPs. TheSTP employs MTP processing to accomplish this function. In addition, theSTP can employ signaling connection control part (SCCP) logic tofacilitate routing. SCCP allows signaling message routing based onlogical connections. For example, a signaling message requesting adialed number translation can be sent to the STP itself. SCCP wouldprovide the STP with the point code for the appropriate database thatcould accommodate the translation.

MTP functionality is comprised of three levels: signaling data link(level 1), signaling link (level 2), and signaling network (level 3).Level 1 represents the bi-directional signal path comprising two datachannels operating together in opposite directions. Level 1 defines thephysical and electrical characteristics of the signaling link.Typically, this entails 56 k/bit data link operation, however, otherforms of links are equally applicable to the present invention. Level 2operates over level 1 to provide for the transfer of signaling frompoint to point over a single data link. This includes delimiting thesignaling messages with flags, bit stuffing, error detection throughcheck bits, error correction through retransmission and sequenceinformation, signal link failure detection, and signal link recovery.For example, on FIGS. 1 and 2, the first two levels might be used toprovide transport over signaling link 20 at 56 k/bit from signalingpoint 10 in switch 30 to signaling point 11 in STP 40. The first twolevels would also ensure that signaling link 20 is monitored for properperformance. Level 3 defines the transport functions that areindependent of the operation of individual signaling links. For example,from switch 30 to SCP 50 on FIG. 2.

SS7 functionality is illustrated in FIG. 3 with MTP 61 and User Part 62.The separation of the MTP and the User Part is shown. The MTP handlestransport of signaling messages within the signaling network and theUser Part facilitates the operation of the network which carriestelecommunications traffic. An example of a user part would be asignaling processor. Signaling Data Link 71 (Level 1) which handles thephysical/electrical transport on individual links is coupled withSignaling Link 72 (level 2) which performs monitoring and control ofthese same individual links. Signaling Network 73, or level 3 is shownbetween the User Part (level 4) and level 2. Level 3 provides theinterface between the User Part and individual link transport. Level 3also manages the SS7 network beyond the individual link level.

FIG. 4 displays this functionality, and particularly level 3functionality, in greater detail. The functions of Signaling Data Link100 (level 1) and Signaling Link 200 (level 2), Signaling Network 300(level 3), and User Part 400 (level 4) have been discussed above.Signaling Network 300 further includes Signaling Message Handling 310which ensures that messages from User Part 400 are delivered to theproper destination primarily according to a routing label contained inthe message. Signal Message Handling 310 is comprised of Discrimination312, Routing 314, and Distribution 316.

Prior to a discussion these elements, a short description of the routinglabel follows. The routing label is contained in each signaling messageand is used by the relevant User Part to identify the purpose of themessage and is used by level 3 to process and route the message. Therouting label is typically placed at the beginning of the signalinginformation field. This routing label contains both a Destination PointCode (DPC) and an Originating Point Code (OPC).

These point codes identify signaling points in the network—and inparticular, the originating and destination signaling point for aparticular message. For example, a message sent from signaling point Ato signaling point B would have an OPC of A and a DPC of B. A returnmessage would reverse the two and have an OPC of B and a DPC of A. Therouting label also contains a Signaling Link Selection (SLS) field whichis used to allow load sharing among links.

Standard international signaling has a 14 bit DPC, 14 bit OPC, and a 4bit SLS. Standard U.S. signaling has a 24 bit DPC, 24 bit OPC, and a 5or 8 bit SLS. The 24 bits of the U.S. point code are broken into three 8bit fields that identify the signaling point, the network, and thenetwork cluster to which the point code belongs. The 8 bit clustermember code 00000000 is reserved for STPs. It should be pointed thatother signaling conventions are equally applicable to the presentinvention.

Referring again to FIG. 4, Discrimination 312 analyzes the DPC of amessage to determine if that particular signaling point (performing thediscrimination function) is the destination of the message. If it is notthe destination, the message is directed to Routing 314 for transfer onthe signaling network. If it is the destination, the message is directedto Distribution 316 for internal processing.

Distribution 316 analyzes the service indicator in the message to directthe message to the appropriate user of User Part 400 or to theappropriate part of Signaling Network Management 320.

Routing 314 accepts messages from Discrimination 312, User Part 400 andSignaling Network Management 320. Routing 314 determines the signalinglink over which these outgoing messages are sent and delivers thesemessages to level 2 for transmission. Typically, the DPC is used toselect a combined link set and the SLS is used to select the link withinthe combined link set on which to place the message. The DPC controlsthe actual destination of the message, but many other factors can affectroute choice such as congestion and link failure. Signaling NetworkManagement 320 provides this type of information to Routing 314.

Signaling Network Management 320 is comprised of the followingfunctions: Signaling Link Management 322, Signaling Route Management324, and Signaling Traffic Management 326. The primary function of theseelements is to provide control of the signaling network in the case offailures and congestion.

Signaling Link Management 322 controls the status of particular links.It may use the following procedures to control the links: linkactivation, link deactivation, link restoration, linkset activation, andautomatic allocation.

Signaling Route Management 324 distributes information about the statusof the links. This information may indicate failed or congested linksand includes: transfer prohibited, transfer allowed, transferrestricted, transfer controlled, signaling route set congestion test,and transfer route set test.

Signaling Traffic Management 326 is used to re-route signaling in orderto respond to system conditions such as failure or congestion. Signalingcan be diverted or partially diverted (inhibited) from one link toanother. These procedures are: changeover, changeback, forcedre-routing, controlled re-routing, MTP restart, management inhibiting,and flow control.

As those skilled in the art are aware, an STP will house the MTPfunctionality discussed above. In accord with the present invention, thefunctionality of the STP can be altered to provide advantageouscapabilities to a telecommunications system.

FIG. 5 depicts the functionality of an STP that is in accord with thepresent invention.

Signaling Data Link 100 (level 1), Signaling Link 200 (level 2),Signaling Network 300 (level 3) and User Part 400 (level 4) are againshown. Additionally, Discrimination 312, Routing 314, Distribution 316,Signaling Network Management 320 are shown as functions of SignalingNetwork 300. These functions interface as discussed above with thefollowing modifications.

Point Code Conversion 500 is added and shown between level 2 and level3. Point Code Conversion 500 accepts the messages from Level 2 andprovides messages to Discrimination 312. Point Code Conversion 500translates the data in the signaling messages using internal tables.Typically, these tables would logically reside in the MTP softwareprocessed by the STP. The tables would be used to systematically changedesignated DPCs, OPCs, and CICs of the signaling messages directed toDiscrimination 312.

The appropriate table could be selected based on the linksets orsignaling clusters that the messages arrive on. These linksets andclusters represent the origin of the messages. The tables could also beselected or entered based on the OPC which also represents the origin ofthe messages. The tables could then use the OPC, DPC and/or CIC of themessages to select new data for the conversion, including a new OPC,DPC, and/or CIC. Because Routing 314 will select the outbound link basedon the DPC, Point Code Conversion 500 can change the actual destinationof the signaling message. The tables would be constructed to effectthese desired changes.

Alternatively, only the DPC could be used for the entire conversion. Onetable would house DPC to DPC conversions. Additionally, at a point inthe STP where processing is still linkset specific (before level 3), MTPlinkset processing could place flags in the messages from designatedlinksets. Those messages coming from the particular linksets wouldaccess the table during subsequent processing when the flag wasdetected, and unflagged messages would not access the table. The tablecould convert combinations of OPC, DPC, and/or CIC into specifiedcombinations of OPC, DPC, and/or CIC.

Referring again to FIG. 4, it can be shown how Discrimination 312 couldbe altered in accord with the present invention. As discussed,Discrimination 312 determines whether the messages are destined for theSTP itself, a User Part, or another signaling point. A conversion tablewhich is based on linkset, OPC, DPC, and/or CIC could be functionallylocated at this point. The table could process all signaling messages,messages not directed to the STP's DPC, or messages flagged in priorprocessing. The present invention thus applies to a point codeconversion function located at Discrimination 312. The convertedmessages would typically be transferred to Distribution 316 in thiscase.

In one embodiment, a Digital Switch Corporation model Megahub STP isused. This STP has a particular feature for gateway screening. Thisfeature screens incoming messages with a set of criteria defined foreach linkset delivering messages. The criteria ensures that the messagesare valid for that linkset. At present, this feature only screensmessages and does not convert them or map point codes. In thisembodiment, the Point Code Conversion 500 is located in the STP betweenlevels 2 and 3 at the point of the gateway screening feature.Alternatively, only a flagging function could be placed at the gatewayscreening feature, and a conversion table could convert flagged messagesduring subsequent processing.

By placing the conversion tables at a point in the STP that is specificto the incoming linkset, the point code conversions can be specified forthe signaling point(s) transmitting signals on the given linkset. Inother words, signaling conversions can be specified individually basedon the origin of the signaling. This placement also allows the level 3functionality to process the converted signal, instead of processing asignal first, and then converting the point codes at the output. Similaradvantages can be attained by flagging the messages on particularlinksets and using the OPC to ascertain the origin during subsequentprocessing.

User Part 400 (level 4) may include a signaling processor, such as thatdescribed in parent application Ser. No. 08/238,605, entitled “Method,System, and Apparatus for Telecommunications Control”, filed on May 5,1994, or in a patent application entitled, “System for ManagingTelecommunications”, filed simultaneously with this application, andassigned to the same assignee. The signaling processor may processparticular ISDN Services User Part (ISUP) signals. In at least oneembodiment, Discrimination 312 would be configured to identify theparticular ISUP messages required by the signaling processor. Thesecriteria could be formed into a table, and the table used to identifythe appropriate ISUP messages from Distribution 312 to transfer to theapplication processor. Like the point code conversion tables, the originof the signaling as represented by the linkset or the OPC could be usedto determine if ISUP should be transferred to the pertinent user part.The OPC, DPC, SLS, CIC and various combinations of these elements couldalso be used for this purpose as well. Those skilled in the art willappreciate other criteria that can be used to route messages to asignaling processor. Additionally, a flagging function could be usedduring linkset specific processing to trigger transfer of ISUP to alevel 4 user during subsequent processing. Those skilled in the art arefamiliar with ISUP identification.

Another embodiment is shown on FIG. 6 which shows the same elements asFIG. 5 except for one addition. In this embodiment, additional pointcode conversion may be required for messages generated by SignalingNetwork Management 320 or User Part 400. For these embodiments, PointCode Conversion 350 is added and shown between Signaling NetworkManagement 320 and Routing 314, as well as, between User Part 400 (level4) and Routing 314. Point Code Conversion 350 operates through the useof tables as does Point Code Conversion 500. In this way, the pointcodes in management messages or from a user part can be converted.Typically, the changes would account for the architectural changes in away similar to Point Code Conversion 500.

As discussed above, Signaling Network Management 320 is comprised ofthree functions: signaling link management, signaling trafficmanagement, and signaling route management. As an example, if asignaling link fails, signaling link management will perceive this andreport it to signaling traffic management which will transmit signals toother signaling points to re-route signaling over an alternate link. Ifthis were to cause congestion on the alternate link, signaling routemanagement would transmit signals to the other signaling pointsinstructing them to restrict use of the congested link.

Typically, signaling link management messages will not need any pointcode conversion. However, signaling traffic management messages andsignaling route management messages both provide other signaling pointswith signaling instructions for affected signaling links and points.Point codes are used to define the affected signaling links and points.These messages will need the identification point codes changed toaccount for new network architectures. These changes are affected bytables as discussed above for the point codes used for routing. Themanagement messages can be specified for each signaling point receivingone of the messages by using the DPC in the routing label to enter thetable. The table would be constructed to give each signaling point whichreceives a management message the point codes it understands in thegiven point code converting scenario.

Another embodiment is shown in FIG. 7 which depicts a telecommunicationssystem including enhanced STP 600 which operates in accord with thepresent invention. STPs 605 and 610 are also shown along with switches615, 620, 625, 630, 635, 640, 645, 650, 655, 660 and 665. STPs 605 and610 are standard STPs which are known in the art. The switches arestandard telecommunications switches which are known in the art.

In FIG. 7, signaling links are represented by the double lines andtelecommunications connections are represented by the single lines. Theswitches and STPs are interconnected with signaling links 700, 705, 710,720, 725, 730, 735, 740, 745, and 750 as shown on the drawing. Theselinks transfer signaling among the switches and STPs as discussed above.The switches are interconnected by connections 760, 765, 770, 775 and780 as shown on the drawing. The connections carry telecommunicationstraffic for users of the telecommunications system as is known in theart.

To understand this embodiment, it should be pointed out that the systemarchitecture has been modified from the following architecture (formerconnections are not shown): a connection from switch 620 to switch 650was re-routed to switch 640, a connection from switch 625 to switch 655was re-routed to switch 645, a connection from switch 630 to switch 660was re-routed to switch 645, and a connection from switch 635 to switch665 was re-routed to switch 645. The connection from switch 615 toswitch 650 did not change. The switches have not been re-programmed toaccommodate signaling in accord with the new architecture. In addition,STPs 605 and 610 have not been enhanced in accord with the presentinvention.

When switch 630 attempts to connect to switch 660 (its formerconnection), it actually connects to switch 645. However, switch 630would still direct signals to switch 660 when it attempts theconnection. The signaling would be routed to STP 600 and would beprocessed in accord with present invention. The DPC in the signalingwould be converted to represent switch 645 instead of switch 660. Thesignaling would then be routed to switch 645. When switch 645 respondsto switch 630 acknowledging the connection, STP 600 will convert the OPCfrom switch 645 to represent switch 660. In this way, switch 630 is ableto signal and make connections in accord the new architecture withoutbeing re-programmed.

When switch 620 attempts to connect to switch 650 (its formerconnection), it actually connects to switch 640 over connection 765.However, switch 620 will still attempt to signal switch 650. The signalwould be routed over link 705 through STP 605 and over link 710 to STP600. The DPC would be converted by STP 600 to represent switch 640instead of switch 650. The signal would then be routed to switch 640over link 745. When switch 615 attempts to connect to switch 650 (itsformer and current connection), it will signal switch 650. The signalwould be routed over link 700 through STP 605 and over link 710 to STP600. In this case, no conversion is needed. Thus, sometimes STP 600should convert the DPC for switch 650, and sometimes it should not. Thepresent invention allows STP 600 to discern whether or not to make theconversion.

STP 600 will identify the source of the signaling before making theconversion. This identification could be by OPC. In this way, theconversions for switch 615 would be different than the conversions forswitch 620. For the OPC of switch 615, the DPC for switch 650 would notbe converted. For the OPC of switch 620, the DPC for switch 650 would beconverted to the DPC for switch 640.

Additionally signaling messages sent in the backward direction couldundergo conversion at the STP in a similar manner. For example, messagesfrom switch 645 to switch 630 and from switch 640 to switch 620 wouldhave their OPC converted to represent switch 660 and switch 650respectively. The message from switch 650 to switch 615 would not needthe OPC to be converted.

Point codes can also be converted at STP 600 based on the signaling linkthat the message arrives on. For example, signaling from switch 650 toswitch 615 does not need conversion, but signaling from switch 640 toswitch 620 does need converted to account for the new architecture. STP600 could be configured to convert the OPCs for signaling messagesarriving on signaling link 745 to the OPC for switch 650. STP 600 wouldnot convert the OPCs for signaling messages arriving on signaling link740. As can be seen, conversion can be based on many factors, such assignaling link, OPC, DPC, CIC, SLS, and various combinations of thesefactors. Other factors are also contemplated by the invention.

As stated above, signaling networks use management messages to controlthe signaling network. An example of such messages is a transferrestricted message. If link 750 between STP 600 and switch 750 becomescongested, the signaling route management function in STP 600 wouldgenerate and transmit transfer restricted messages to alleviatecongestion on link 750. In the signals, the congested link is defined bythe point code for switch 645 (the message would still require aseparate OPC and DPC in the routing label for its own routing). However,the other switches in the network would not recognize the point code forswitch 645 because they have not been reprogrammed. As such, they wouldnot recognize the congested link, and might continue to inadvertentlyuse it. STP 600 would convert the point codes in the management messageswhich define the congested link to point codes that would be recognizedand properly acted upon by the signaling points receiving the managementmessages.

Each signaling point to receive a transfer restricted message could geta specific conversion. This is accomplished by using the DPC in therouting label of the management message to identify the receivingsignaling points and obtain the specified conversion. For example, thepoint code defining the congested link might be of switch 655 for themessage sent to switch 625, and it might be of switch 660 for themessage sent to switch 630. In this case the DPCs in the routing labelswould be used to access the specified conversions for the point codedefining the congested link. In some cases conversion may be not berequired for certain management message destinations. For example, atransfer restricted message regarding link 740 that is sent to switch615. Message origination recognition could be used to discern whetherconversion is required.

FIG. 8 depicts another embodiment of the invention. Switch 810 is shownlinked to STP 830 and switch 820 is shown linked to STP 840. Signalingprocessor 850 is shown coupled to STP 830, and signaling processor 860is shown linked to STP 830 and to STP 840. If switch 820 sends a messageto switch 810 through STP 840, STP 840 could convert the DPC torepresent the point code for signaling processor 860. As such, themessage would be routed to signaling processor 860. A message fromsignaling processor 860 to switch 820 could have the OPC converted bySTP 840 to represent the OPC of switch 810. In this way switch 820 doesnot need to be re-programmed with the point code for signaling processor860.

In addition, signaling processor 850 could function as a user part ofSTP 830. If switch 810 were to transmit a signal to switch 820, STP 830could forward the signal to signaling processor 850 instead of switch820. After processing the message, the signaling processor couldtransmit a message to switch 820 and STP 830 could convert the OPC to bethat of switch 810. Messages from switch 820 to switch 810 could betreated in a similar fashion. In this way, signaling processor 850 canprocess the signaling between the switches in a way that was transparentto the switches.

There are many advantages gained from the present invention. Whennetwork architectures change, switches do not need to be re-programmedto signal each other in accord with the new architecture. This avoids acomplex and time consuming task.

Because the present invention acts on signaling as enters MTP level 3processing, multiple switches can be accommodated. Signaling directed toany switch in the network which passes through the STP can be converted.Prior systems only converted signaling after the route function of MTPlevel 3. The present invention allows one integrated and flexible systemthat acts on MTP level 3 input.

Because the present invention does not rely on individual trunkidentification, it can efficiently address situations in which entireswitch loads are moved between switches, or when multiple switch loadsare consolidated on a single switch. In these cases, individual trunkrecognition is unnecessary.

The present invention is capable of selecting destinations for signalingmessages based on the origin of the messages. This allows conversions tobe tailored for each source of signaling. Prior systems did not selectsignaling destinations which corresponded with the origin of themessage, but based the selection on individual trunk identification orthe destination point code.

The present invention can also accommodate the introduction of signalingprocessors into a network. Using the STP of the present invention, thesignaling processors can avoid using point codes altogether or have apoint code that is transparent to the rest of the network.

The present invention provides an efficient and operational STP whichcan convert signaling to accommodate architectural changes affectingseveral switches in a large network. The specification and figuresprovide embodiments of the present invention, but the present inventionis not limited to these specific embodiments. Those skilled in the artcan appreciate many applications of the present invention, which shouldbe measured in accord with the following claims.

What is claimed is:
 1. A signal transfer point (STP) comprising: a firstmeans for processing signaling messages containing point codes to applya message transfer part (MTP) signaling data link function; a secondmeans for processing the signaling messages to apply an MTP signalinglink function; a third means for processing the signaling messages toapply an MTP signaling network function wherein the MTP signalingnetwork function includes generating signaling management messages; anda converting means for converting at least some point codes intodifferent point codes in the signaling messages and the signalingmanagement messages, wherein the signaling messages converted by theconverting means are received by the STP.
 2. The STP of claim 1 whereinthe signaling messages are SS7 messages.
 3. The STP of claim 1 whereinthe signaling messages are C7 messages.
 4. A signal transfer point (STP)comprising; a first means for processing signaling messages containingdestination codes to apply a message transfer part. (MTP) signaling datalink function; a second means for processing the signaling messages toapply an MTP signaling link function; a third means for processing thesignaling messages to apply an MTP signaling network function whereinthe MTP signaling network function includes generating signalingmanagement messages; and a converting means for converting at least someof the destination codes into different destination codes in thesignaling messages and the signaling management messages, wherein theconverting means selects the different destination codes for thesignaling messages using information related to origins of the signalingmessages, wherein there are a plurality of different origins and eachselected destination code corresponds to one of the different originsand wherein the signaling messages converted by the converting means arereceived by the STP.
 5. The STP of claim 4 wherein the messages aretransferred on a plurality of signaling links which are grouped intolinksets and the origin information is particular linksets on which themessages are transferred to the STP.
 6. The STP of claim 4 wherein themessages from a particular linkset are flagged.
 7. The STP of claim 4wherein the origin information is originating codes.
 8. A signaltransfer point (STP) comprising; a first means for processing signalingmessages containing point codes to apply the signaling data linkfunction; a second means for processing the signaling messages to applyan MTP signaling link function; a third means for processing thesignaling messages to apply an MTP signaling network function and fortransferring integrated services user part (ISUP) messages to the UserPart wherein the MTP signaling network function includes generatingsignaling management messages; and a converting means for converting atleast some of the point codes into different point codes in thesignaling messages and the signaling management messages wherein thesignaling messages converted by the converting means are received by theSTP.
 9. The STP of claim 8 wherein the ISUP messages are transferred tothe User Part in based on origination point codes in the messages. 10.The STP of claim 8 wherein the ISUP messages are transferred to the UserPart in based on destination point codes in the messages.
 11. The STP ofclaim 8 wherein the ISUP messages are transferred to the User Part inbased on circuit identification codes in the messages.
 12. A signaltransfer point (STP) comprising; a first means for processing signalingmessages containing destination codes to apply a message transfer part(MTP) signaling data link function; a second means for processing thesignaling messages to apply an MTP signaling link function; a thirdmeans for processing the signaling messages to apply an MTP signalingnetwork function wherein the MTP signaling network function includesgenerating signaling management messages; and a converting means forconverting at least some of the destination codes into new destinationcodes in the signaling messages and the signaling management messages byusing the destination codes from the signaling messages to enter a tableand obtain the new destination codes wherein the signaling messagesconverted by the converting means are received by the STP.
 13. The STPof claim 12 wherein the table is used to obtain the new destinationcodes only for signaling messages from a particular linkset.
 14. The STPof claim 12 wherein the converting means is further for converting atleast some circuit identification codes in the signaling messages intonew circuit identification codes.
 15. The STP of claim 12 wherein thesignaling messages are SS7 messages.
 16. The STP of claim 12 wherein thesignaling messages are C7 messages.
 17. A signal transfer point (STP)comprising; a first means for processing signaling messages containingdestination codes to apply a message transfer part (MTP) signaling datalink function; a second means for processing the signaling messages toapply an MTP signaling link function; a third means for processing thesignaling messages to apply an MTP signaling network function whereinthe MTP signaling network function includes generating signalingmanagement messages; and a converting means for converting at least someof the destination codes in the signaling messages into new destinationcodes by using origination codes from the signaling messages to enter atable and obtain the new destination codes wherein the signalingmessages converted by the converting means are received by the STP. 18.The STP of claim 17 wherein the converting means is further forconverting at least some of the origination codes in the signalingmessages into new origination codes by using the origination codes fromthe signaling messages to enter the table and obtain the new originationcodes.
 19. The STP of claim 17 wherein the converting means is furtherfor converting at least some circuit identification codes in thesignaling messages into new circuit identification codes.
 20. The STP ofclaim 17 wherein the signaling messages are SS7 messages.
 21. The STP ofclaim 17 wherein the signaling messages are C7 messages.
 22. A signaltransfer point (STP) comprising; a first means for processing signalingmessages containing point codes to apply an MTP signaling data linkfunction; a second means for processing the signaling messages to applyan MTP signaling link function; a third means for processing thesignaling messages to apply an MTP signaling network function whereinthe MTP signaling network function includes generating signalingmanagement messages; and a converting means for converting at least somecircuit identification codes into new circuit identification codes inthe signaling messages and the signaling management messages-based onthe point codes in the signaling messages wherein the signaling messagesconverted by the converting means are received by the STP.
 23. The STPof claim 22 wherein the signaling messages are SS7 messages.
 24. The STPof claim 22 wherein the signaling messages are C7 messages.
 25. A methodfor operating a Signal Transfer Point (STP), the method comprising:applying a message transfer part (MTP) signaling data link function tosignaling messages containing point codes; applying an MTP signalinglink function to the signaling messages; applying an MTP signalingnetwork function to the signaling messages wherein the MTP signalingnetwork function includes generating signaling management messages; andconverting at least some of the point codes into different point codesin the signaling messages and the signaling management messages, whereinthe signaling messages are received by the STP.
 26. The method of claim25 wherein the signaling messages are SS7 messages.
 27. The method ofclaim 25 wherein the signaling messages are C7 messages.
 28. A methodfor operating a Signal Transfer Point (STP), the method comprising;applying a message transfer part (MTP) signaling data link function tothe signaling messages; applying an MTP signaling link function to thesignaling messages; applying an MTP signaling network function to thesignaling messages wherein the MTP signaling network function includesgenerating signaling management messages; and converting at least someof the destination codes into different destination codes in thesignaling messages and the signaling management messages by selectingthe different destination point codes for the signaling messages usinginformation related to origins of the signaling messages, wherein thereare a plurality of different origins and each selected destination pointcode corresponds to one of the different origins and wherein thesignaling messages are received by the STP.
 29. The method of claim 28wherein the messages are transferred on a plurality of signaling linkswhich are grouped into linksets and the origin information is particularlinksets on which the messages are transferred to the STP.
 30. Themethod of claim 28 further comprising flagging the messages from aparticular linkset.
 31. The method of claim 28 wherein the origininformation is originating point codes.
 32. A method for operating anSignal Transfer Point (STP), the method comprising; applying a messagetransfer part (MTP) signaling data link function to signaling messagescontaining point codes; applying an MTP signaling link function to thesignaling messages; applying an MTP signaling network function to thesignaling messages and transferring integrated services user part (ISUP)messages to a User Part wherein the MTP signaling network functionincludes generating signaling management messages; and converting atleast some of the point codes into different point codes in thesignaling messages and the signaling management messages and wherein thesignaling messages are received by the STP.
 33. The method of claim 32wherein the ISUP messages are transferred to the User Part in based onorigination point codes in the messages.
 34. The method of claim 32wherein the ISUP messages are transferred to the User Part in based ondestination point codes in the messages.
 35. The method of claim 32wherein the ISUP messages are transferred to the User Part in based oncircuit identification codes in the messages.
 36. A method for operatinga Signal Transfer Point (STP), the method comprising; applying a messagetransfer part (MTP) signaling data link function to signaling messagescontaining destination codes; applying an MTP signaling link function tothe signaling messages; applying an MTP signaling network function tothe signaling messages wherein the MTP signaling network functionincludes generating signaling management messages; and converting atleast some of the destination codes into different destination codes inthe signaling messages and the signaling management messages by usingthe destination codes from the signaling messages to enter a table andobtain the new destination codes and wherein the signaling messages arereceived by the STP.
 37. The method of claim 36 wherein the table isused to obtain the new destination codes only for signaling messagesfrom a particular linkset.
 38. The method of claim 36 further comprisingconverting at least some circuit identification codes in the signalingmessages into new circuit identification codes.
 39. The method of claim36 wherein the signaling messages are SS7 messages.
 40. The method ofclaim 36 wherein the signaling messages are C7 messages.
 41. A methodfor operating an Signal Transfer Point (STP), method comprising;applying a message transfer part (MTP) signaling data link function tosignaling messages containing destination codes; applying an MTPsignaling link function to the signaling messages; applying an MTPsignaling network functiion includes generating signaling managementmessages; and converting at least some of the destination codes intodifferent destination codes in the signaling messages and the signalingmanagement messages by using origination codes from the signalingmessages to enter a table and obtain the new destination codes andwherein the signaling messages are recieved by the STP.
 42. The methodof claim 41 further comprising converting at least some of theorigination codes in the signaling messages into new origination codesby using the origination codes from the signaling messages to enter thetable and obtain the new origination codes.
 43. The method of claim 41further comprising converting at least some circuit identification codesin the signaling messages into new circuit identification codes.
 44. Themethod of claim 41 wherein the signaling messages are SS7 messages. 45.The method of claim 41 wherein the signaling messages are C7 messages.46. A method for operating an Signal Transfer Point (STP), the methodcomprising; applying a message transfer part (MTP) signaling data linkfunction to signaling messages containing point codes; applying an MTPsignaling link function to the signaling messages; applying an MTPsignaling network function to the signaling messages wherein the MTPsignaling network function includes generating signaling managementmessages; and converting at least some circuit identification codes intonew circuit identification codes in the signaling messages and thesignaling management messages based on the point codes in the signalingmessages and wherein the signaling messages are received by the STP. 47.A method for operating a telecommunications system, the methodcomprising: receiving signaling messages containing destination codesinto a signal transfer point (STP); converting the destination codes toidentify a signaling processor; and routing the signaling messagesthrough a message transfer part level 3 distribution function to thesignaling processor based on the converted destination codes, whereinthe signaling processor operates as a user part to the STP.
 48. Themethod of claim 47 further comprising receiving the signaling messagesinto the signaling processor.
 49. The method of claim 47 furthercomprising generating the signaling messages in a plurality of switchesand transmitting the signaling messages to the STP.
 50. The method ofclaim 47 wherein the signaling messages are C7 messages.